Modern dental chairs include mechanisms for raising and lowering the chair seat and for tilting the back of the chair. A patient enters the chair while the chair is positioned with the back upright and with the seat elevated to a level that permits the patient to move comfortably from a standing to a sitting position. After the patient sits in the chair, the dentist or technician operates the chair to move the patient into the position selected by the dentist as appropriate for the dental procedure that is to be undertaken. For many procedures, the chair seat is raised and the back is tilted so that the patient assumes a recumbent position.
The patient's comfort is an important design consideration with respect to dental chairs. In this regard, the chair should be configured so that the patient is comfortable irrespective of the chair position. Moreover, the motion of the chair components should be directed to minimize sliding of the patient within the chair as the chair is moved from one position to another.
Another important dental chair design consideration may be generally characterized as maximizing the convenience of the dentist. In this regard, the efficiency of the dental procedure is enhanced when the mechanisms for moving the chair permit the dentist to easily and precisely position and reposition the chair. Moreover, the chair should be configured to allow the dentist to assume a position close to the patient while the dentist remains seated.